Automatic truck body cover



Dec. 2, 1969 G. STEPP AUTOMATIC TRUCK BODY COVER 4 Sheets-Sheet 1 FiledAug. 4. 1967 MW E WT VS W G l.- L E W O LY B m=h ATTORNEY Dec. 2', 1969L. G. STEPP 3,481,645

AUTOMATIC TRUCK BODY COVER Filed Aug. 4, 196'? 4 Sheets-Sheet 2INVENTOR.

LOWELL G. STEPP wfww ATTORNEY Dec. 2, 1969 L. G. STEPP 3,481,645

AUTOMATIC TRUCK BODY COVER Filed Aug. 4, 1967 4 Sheets-Sheet 3 NVFNTOR.

LOWELL G. STEPP BY A W6 MW ATTORNEY Dec. 2, 1969 L. G. STEPP 3,431,645

AUTOMATIC TRUCK BODY COVER 4 Sheets-Sheet 4 Filed Aug. 4 1967 FIG. 8

INVENTOR. LOWELL G. STEPP BY M/(W ATTORNEY United States Patent3,481,645 AUTOMATIC TRUCK BODY COVER Lowell G. Stepp, Syracuse, Kans.67878 Filed Aug. 4, 1967, Ser. No. 658,414 Int. Cl. B60j 7/04, 7/06 US.Cl. 296-105 18 Claims ABSTRACT OF THE DISCLOSURE A truck provided with apower driven extensible and retractable flexible roof or tarpaulin, suchroof being supported on a plurality of bows mounted on a series ofmovable carriers. The movable carriers are supported and guided uponelongated hollow guides detachably mounted on the side walls of thetruck bed. Each carrier has a grooved upper roller engaged on a rib onthe top of the guide and a lower ribbed roller engaged in a slot on thebottom of the guide. The carriers of the rearmost bow are detachablyconnected to selected positions along a drive chain sheltered within thehollow guides by forks extending through the slots in the bottoms of theguides.

In order to reduce air movement between the rear end of the extendedroof and the top of the tail gate, the latter is pivotally provided witha latchable closure member having an upper periphery conformable to theconfiguration of the rearmost bow.

The chains are entrained over driving and driven sprockets, the drivingsprockets are fixed on a common drive shaft that is severable tofacilitate detachment of the guides from the truck.

The bows are slidingly extensible to compensate for variations in guidespacing, especially such variations as may occur due to the side wallsbeing bulged outwardly by cargo.

Electrical control means operable from the truck operators position isprovided which includes forward and reverse electric circuits, withswitch means being provided for disabling such circuits respectivelyupon the rearmost bow reaching relatively forward and rear positions.

The present invention relates to new and useful improvements in supportand guide means per se, and particularly pertains to such means incombination with power driven retractable and extensible collapsibleroofs or tarpaulins for the cargo space of cargo carrying vehicles ortrucks.

Numerous proposals have heretofore been made in connection withextensible and retractable tarpaulin covers for truck beds. Anappreciation of the general character of proposals hereto-fore made andthe purposes of such proposals may be obtained upon making reference tothe following US. Letters Patents:

3,160,436, Dudleston, Tarpaulin superstructure for Trailers, December1964;

2,882,091, Shield, Collapsible Cover For Vehicle Be'ds, Apr. 14, 1959;

3,041,104, Richard, Device For Unrolling the Canvas Top of a TrailerTruck, June 26, 1962;

2,559,310, McNavage, Collapsible Cover For Vehicles, July 3, 1951; and,

2,469,958, Fowler, Motor Vehicle Cover, May 10, 1949.

The paramount object of the present invention is to provide a supportand guide structure having a high degree of reliability, particularly inbeing virtually free of any susceptibility to being jammed or blocked bythe intrusion of any foreign matter.

Another important object of the present invention is to provide arelationship between a tarpaulin supporting 3,481,645 Patented Dec. 2,1969 "Ice bow and guides supporting the opposite ends of the bow such asto possess a high degree of reliability notwithstanding relativemovement of the guides such as may occur due to any variation in thespacing of the guides due to cargo loading, and the like.

Still another important object of the present invention is to provide anextensible tarpaulin cover in such a combination with a truck that airmovement within the covered area be minimized, and especially so thatair movement between the rear end of the extended tarpaulin cover andthe endgate of the truck be minimized.

Yet another important object of the invention is to provide a guide andcarrier such that a rolling engagement is established between thecarrier and the guide with such rolling engagement being such as toserve the guiding and supporting function and such engagement beingestablished along surfaces not readily susceptible to theinterpositioning of or retention of obstructing foreign matter.

Another object closely related to the last mentioned object is toprovide a guide and carrier such that relative angular movement aboutany axis is precluded or extremely limited, it is preferable andtherefore a further object of the present invention to attain suchobjective in such a manner that a series of carriers can be relativelymovable on a single guide, with such carriers being such as to be atleast partially neste'd with respect to each other so as to minimize theextent of the guide occupied by the series of carriers.

A final important object of the present invention to be specificallyenumerated is to provide a power driven extensible and retractabletarpaulin or flexible roof cover for a truck with operative controlsaccessible to the truck operator with such operative controls being madeinoperative to retract or extend the tarpaulin when the latter is fullyretracted and fully extended respectively.

A broad aspect of the invention involves the provision of apparatus forsupporting, guiding and moving a carrier comprising an elongated andhorizontally extending hollow guide, said guide having a longitudinallyextending slot opening into the interior thereof, a carrier disposed ata side of the guide and provided with vertically spaced upper and lowerrollers respectively disposed above and below the guide to engage thetop and bottom of the guide, a pair of chain sprockets mounted adjacentopposite ends of the guide, an endless chain disposed within the guideand entrained over the sprockets, and means extending through the slotand operatively connecting the carrier and the chain.

Another broad aspect of the invention involves, in apparatus for theguided support and movement of a retractable and extensible flexibleroof structure of the type including a pair of parallel elongatedsupport guides adapted to be mounted horizontally on the opposite sidesof the roof-coverable area, and roof bow support means guidinglysupported on the guides, the improvement comprising each of said guidesbeing hollow and having an endless drive chain extending therein withinthe hollow thereof, sprockets carried by the guide adjacent the oppositeends thereof with said endless chain being entrained over saidsprockets, each of said how support means including a supported andguided member, vertically spaced laterally projecting stub axles on saidmember, an upper roller rotatably mounted on the uppermost of said stubaxles, said upper roller being disposed on top of the guide and inperipheral rolling engagement thereon, with the top of the guide and thecircumferential periphery of the upper roller having meshing rib andgroove means for preventing axial movement of the upper roller relativeto the guide, a lower roller rotatably mounted on the lowermost of thestub axles, said lower roller being disposed on the bottom of the guideand in close peripheral rolling proximity thereto, with the bottom ofthe guide and the circumferential periphery of the lower roller havingmeshing rib and groove means for preventing axial movement of the lowerroller relative to the guide, said guide having a longitudinallyextending slot therein opening into said hollow, an upright member of atleast one of said support means having an operative connection with thechain through said slot.

Still another important aspect of the invention involves, in thecombination of a self-propelled cargo vehicle of the type including atruck bed having an upstanding front and end wall, spaced upstandingside walls, and a rectangular endgate pivotally mounted along an edge tothe rear edge of the truck bed with a retractable and extensible roof offlexible material having a front edge secured to the front end wall andsupported by a series of relatively movable bows supported and guidedfor forward and rearward movement upon guides carried by the side walls;the improvement wherein each of the bows is generally of an invertedU-shaped configuration including depending leg portions connected by aweb portion, and wherein the bows are supported and guided by a pair oflongitudinally hollow guides carried by and extending along the sidewalls, each leg portion of each bow being provided with a carriermovably mounted on one of said hollow guides, said hollow guide having alongitudinally extending slot in the bottom thereof opening into thehollow interior of the guide, said hollow guide having a longitudinallyextending rib along the top thereof, said carrier having an upper rolleron the top of the guide, such upper roller having a peripheral groovereceiving the rib therein, said carrier having a lower roller on thebottom of the guide, such lower roller having a peripheral rib receivedin the slot, driving and driven chain sprockets mounted on the guideadjacent the opposite ends of the guide, and an endless chain within thehollow guide and entrained over the sprockets, means operativelyconnecting the carriers of the leg portions of the rearmost bow to thechains within the guides, the last recited means extending through theslots of the guides, and means for reversibly driving the drivingsprockets in unison.

An important feature of the present invention resides in the provisionof a hollow guide constituting a housing for an endless chain, the topof the housing being formed as a rib received in a grooved roller of acarrier, and the bottom of the guide being provided with a slot forreceiving a ribbed roller of the carrier, such slot in addition toserving a guiding function also serving the function of accommodating adriving connection between the endless chain and the carrier. Anassociated feature resides in the driving connection between the endlesschain and the carrier taking the form of a forked element carried by thecarrier and engageable with a selected portion of the extent of theendless chain.

Another important feature of the invention resides in adjacent carriersbeing alternately provided with single upper and dual lower rollers, andvice versa, whereby the carriers can be at least partially nested witheach other as to the longitudinal extent of the guide.

Still another important feature of the invention resides in theprovision of a closure wall pivoted on the conventional tail gate of thetruck for selectively closing the space between the top of the tail gateand the rearmost edge portion of the tarpaulin, whereby air movement ordrafts through such space can be greatly reduced and thereby minimizeany possibility of loss of cargo, such as grain, over the tail gate.

A final feature of importance to be specifically enumerated resides inthe provision of means for interrupting selectively electrical circuitscontrolling extension and retraction of the tarpaulin when the tarpaulinis fully extended and fully retracted, respectively.

These and other objects, aspects and features of the invention willbecome manifest during the ensuing de- .4 scription of the preferredembodiment of the invention, such description to be taken in conjunctionwith the accompanying drawings, wherein:

FIGURE 1 is a side elevational view of a truck provided with theextensible and retractable tarpaulin structure of this invention, thisview showing the tarpaulin in extended position, with portions of thetarpaulin being broken away;

FIGURE 2 is a view similar to FIGURE 1; however, this view showing thetarpaulin in a nearly fully retracted condition, and with portions ofthe tarpaulin broken away;

FIGURE 3 is a broken and enlarged sectional detail view taken upon theplane of the broken section line 33 of FIGURE 4, portions of thestructure being shown in side elevation;

FIGURE 4 is an enlarged fragmentary side elevational view of the rearend portion of one of the guides and of the rearmost carrier on suchguide, portions of the structure being broken away and shown in dashedoutline to reveal hidden details;

FIGURE 5 is an enlarged fragmentary side view of a portion of one of theguides and of one of the carriers mounted thereon, portions of thestructure being shown in dashed outline to reveal hidden detailsthereof;

FIGURE 6 is a broken isometric view of the forward end of the guides,the means for driving the sprockets, and the limit switches constitutinga part of the controlled drive of the chain, portions of the structurebeing broken away to reveal hidden details;

FIGURE 7 is a schematic diagram of the electrical circuitry of theelectrical driving means;

FIGURE 8 is a fragmentary isometric view of the rear end of the truckshown in FIGURES 1 and 2, this view illustrating the rear ends of theguides and a closure member mounted on the upper edge of the tail gate,the tail gate and the closure member being shown in closing positions;

FIGURE 9 is a fragmentary side elevational view of the rear end of thetruck, and illustrates in dashed outline the closure member swung fromits closing position shown in full lines; and,

FIGURE 10 is an enlarged vertical sectional detail view taken upon theplane of the section 10-10 in FIGURE 8.

Referring now to the drawings wherein like numerals designate like partsthroughout the various views, the reference numeral 10 designatesgenerally a self-propelled cargo vehicle or truck which, as isconventional, includes an operators cab 12 from within which the truckoperator, not shown, can control or operate the truck 10 as well as aflexible roof structure designated generally at 14 of extensible andretractable character by means presently to be described. As isconventional, the truck 10 includes an engine compartment 16, dirigiblefront wheels 18, and rear drive wheel 20.

The truck 10 also includes, as is conventional, a frame 22 upon the rearportion of which is mounted a rectangular truck bed 24 at the forwardend of which is an upstanding front wall 26 that extends between theforward edges of spaced side walls 28 and 30 upstanding along theopposite sides of the truck bed 24. A conventional endgate 32 extendsupwardly from the rear end of the truck bed 24 and between the rear endedges of the side walls 28 and 30. The endgate 32 can be immovable withrespect to the truck bed 24 and the side walls 28 and 30, as shown, oralternatively the endgate 32 can be pivotally connected if desired alongits lower edge to the truck bed 24. Though not illustrated in thedrawings, it is to be understood that, as is conventional, the truck bed24 can be pivotally mounted upon the frame 22 and provided withhydraulic actuators and control means whereby the same can be tiltedabout a transverse horizontal axis adjacent the rear end of the truckbed 24 in a clockwise direction to a dumping position.

Although not constituting a part of the present invention per se, itwill be appreciated by those familiar with the art that the front Wall26, the side walls 28 and 30 as well as the endgate 32 may includedetachable upper extensions, whereby the volume of the cargo to becarried by the truck can be increased. Such provision of verticalextensions for front and side walls, as well as for endgates, is quitecommonplace upon trucks such as employed by farmers for use in carryinggrain such as wheat, and the like.

Thus far, excepting only the roof structure 14 briefly alluded to, thestructure is entirely conventional and does not in and of itselfconstitute the subject matter of the present invention.

With the foregoing description of conventional truck construction as abackground, the subject matter co nstituting the present invention willnow be described.

The roof structure 14 is provided with means for guiding and supportingthe same, such means including a pair of elongated hollow guides 36 and38. The elongated hollow guides 36 and 38 are horizontally disposed andare positioned outwardly from the opposite sides of the side walls 28and 30 at a position adjacent the upper edges of such side walls. Aswill be noted on inspection of FIGURES l and 2, the guides 36 and 38 aresomewhat longer than the truck bed 24 and extend from positions inadvance of the forward wall 26 to positions rearwardly of the endgate32. The guides 36 and 38 are identical to each other, being mirrorimages of each other, and a detailed description of the guide 36 willsuflice for both of the guides 36 and 38.

As best shown in FIGURE 3, the guide 36 comprises parallel verticalsides 40 and 42 that are spaced apart to define the hollow interior 44of the guide 36, the spacing of the sides 40 and 42 being substantiallyless than the vertical extent of such sides 40 and 42 as will be plainlyapparent .on inspection of FIGURE 3. Adjacent the upper end of the guide36, the sides 40 and 42 are bent at 46 and 48 to converge upwardly at 50and 52 respectively, and from their position of convergence 54, thesides 40 and 42 extend a short interval upwardly in flush engagementwith each other to define an upstanding rib 56 that extends centrallyalong the top of the guide 36 for the entire longitudinal extent of theguide 36. The side walls 40 and 42 of the guide 36 are formed of sheetsteel, and the flush portions thereof constituting the rib 56 aresuitably welded together, as by spot welding or the like, so as toconstitute an integral structure.

The lower marginal portions of the side walls 40 and 42 are inwardlybent as at 58 and 60, respectively, and the lowermost margins areinwardly crimped or folded upon themselves as at 62 and 64, thearrangement being such as to reinforce or rigidify the lower part of theguide 36 and to define an opening or longitudinally extending slot 66between the crimped portions 62 and 64 opening centrally from the bottomof the guide 36 upwardly into the hollow interior 44 of the guide 36.Additionally, the folded and crimped lower portions of the side walls 40and 42 serve to defiene downwardly facing rolling contact surfaces 68and 70 on the opposite sides of the slot 66.

A horizontal and longitudinally extending partition 70 is disposedwithin the hollow interior 44 of the guide 36, the same being spacedabove the slot 66 and being spaced below the position of convergence 54,and preferably more closely spaced to the slot 66 as shown. Thepartition 70 serves to divide the hollow interior 44 of the guide 36into upper and lower portions 72 and 74 as shown. Preferably, thepartition 70 is the web portion of a longitudinally extending memberthat is of an inverted U-shape transverse section including legs 76 and78 seated flush against and suitably secured as by spot welding or thelike to the adjacent faces of the side walls 40 and 42. Preferably, theleg portions 76 and 78 connected by the web 70 have their lower edgesdisposed in close proximity to the crimped portions 62 and 64, as shown.The partition or web 70 serves to reinforce the side walls 40 and 42 andto maintain the spacing of the side walls 40 and 42, especially adjacentthe slot 66. The partition 70 serves yet another function that will besubsequently described.

The horizontal partition 70 only extends an intermediate portion of thelongitudinal extent of the guide 36, and adjacent the forward end of theguide 36 and forwardly of the forward end of the partition 70 there is achain sprocket 80 disposed within the hollow interior 44 of the guide36, such chain sprocket 80 being disposed on a shaft 82 journaledthrough the side walls 40 and 42. In a similar manner, a chain sprocket84 is provided within the forward end portion of the guide 38, thesprocket 84 being fixed to a shaft similarly journaled through the sideWalls of the guide 38. The front end of the hollow guide is closed by acup 85 removably fitted thereover and removably held in place by thescrews shown.

The rear end of the guide 36 is closed by a cup 86 removably fittedthereon (see FIGURE 4), and a slide 88 is disposed within the rear endof the hollow interior 44 of the guide 36, such slide 88 beinglongitudinally movable within the guide 36. The slide 88 is disposedrearwardly of the rearmost end of the partition 70, and such slide 88 ishollow and has an axle fixed therein, and a chain sprocket 92 isjournaled for rotation on the axle 90. The slide 88 is provided with apair of rearwardly extending threaded members 94 that are fixed thereto,and such threaded members 94 extend through aligned apertures 96 in theclosure cup 86. An endless chain including upper and lower flights 98and 100, respectively, is entrained over the sprockets 80 and 92, thechain being disposed in the hollow interior 44 of the guide 36, with theupper and lower flights 98 and 100 thereof being respectively disposedin the upper end lower portions 72 and 74 of the hollow interior 44. Thearrangement is such that the chain may be adjusted to obtain or maintainthe desired degree of tautness or tension by the tightening of nuts 102J on the threaded members 94. It is not essential that the chainbemaintained under a particularly great degree of tension in order tomaintain separation of the upper and lower flights 98 and 100 inasmuchas the partition 70 maintains separation of the upper and lower flights98 and 100 of the chain. Indeed, the chain may be sufliciently relaxedin tension so that an intermediate portion of the upper flight 98thereof slides upon and is supported by the partition 70. It should benoted at this juncture of the description that the transverse width ofthe slot 66 is substantially less than that of the chain so that thelatter can slide upon and be supported by the crimped portions 62 and 64of the side walls 40 and 42 without passing downwardly through or eveninto the slot 66.

At spaced positions along the longitudinal extent of the guide 36, thereare attached as by welding or the like vertical lengths of angle iron106 so as to provide longitudinally spaced vertically extending flanges108 directed toward the side wall 28 of the truck 10. The side wall 28(as is similarly true of the side wall 30) includes vertically extendingmembers such as those indicated at 110 (see FIGURES 1 and 3), and thelongitudinally spaced flanges 108 are seated against the rear verticalsides of the members 110, the flanges 108 and the members 110 beingsimilarly spaced, and as shown in FIGURE 3, the flanges 108 aredetachably secured to the members 110 by means of threaded fastenersindicated at 112. The members 110 can be either wood or steel, and thethreaded fastening means 112 can either be threaded into suitablypositioned internally threaded apertures in the members 110, or thethreaded means 112 can be nuts and bolts passing through the flanges 108and the members 110. It will be evident to those familiar with the artthat the members 110', at least the portions thereof to which theflanges 108 are attached, can constitute portions of removable verticalextensions such as conventionally employed in trucks to enablevertically extending the side walls 28 and 30. It will also be evidentthat when the portions of the members 110 to which the flanges 108 areattached are detachable from the lower portion of the side wall 28, suchdetachable portion of the side wall 28 can be removed from the side wall28 along with the guide 36 as a unit. From the foregoing, it will beclear that the guide 38 is not only similarly attached to the upperportion of the side wall 30, but that the guide 38 can also bedetachably removed along with the upper detachable portion of the sidewall 30, should the latter be detachable as previously described inconnection with the side wall 28.

The guides 36 and 38 are mounted upon the side walls 28 and of the truckin such a manner that the shafts 82 and 85 of the sprockets and 84 arein alignment and at a position forward of the front wall 26 of the truck10. Means is provided for detachably coupling the shafts 82 and so thatthe sprockets 80 and 84 can be compelled to rotate in unison. Thedesirability for the provision of means for detachably coupling theshafts 82 and 85 resides in the fact that such detachable couplingenables the guides 36 and 38 to be individually removed or attached tothe truck 10 either as separate units or as units attached to upperdetachable portions of the side walls 28 and 30 as previously mentioned.The means for detachably coupling the shafts 82 and 85 comprises aconnecting shaft 116 provided with socket portions 118 and 120 at itsopposite ends which respectively slidingly receive the adjacent ends ofthe shafts 82 and 85. The socket portion 118 is provided with alongitudinally extending slot 122 into which is received a radiallyextending pin 124 fixed to the shaft 82. The arrangement is such thatthe connecting shaft 116 can be moved to the left as viewed in FIGURE 6to disconnect the shafts 82 and 116, but that when the shaft 116 isaxially moved to the right so as to receive the shaft 82 in the socketportion 118 with the pin 124 disposed in the slot 122, the shafts 82 and116 are not only maintained in alignment, but are compelled to rotate inunison. v

In a similar manner, the socket portion 120 is provided with a slot 126which receives a pin 128 fixed to the shaft 85. A coiled compressionspring 130 embraces the shaft 85 and is biased between the extremity ofthe socket member 120 facing the guide 38 and the guide 36. Thearrangement is such that the spring 130 yieldingly urges the shaft 116to the right as viewed in FIGURE 6. The spring 130 causes such movementof the shaft 116 that the shaft 82 bottoms out in the socket portion118. The dimensions of the socket portion 120 of the connecting shaft116 are such that when the shaft 82 is bottomed out in the socketportion 118, the shaft 85 is not bottomed out within the socket portion120, but the pin 128 is disposed within the slot 126. It will beunderstood that when it is desired to decouple the shafts 82 and 85 fromtheir coupled relationship shown in FIG- URE 6, the connecting shaft 116is moved to the left as viewed in FIGURE 6 against the bias of thespring 130 to an extent sufficient to free the shaft 82 from the socketportion 118, whereupon the socket portion 118 is moved laterally asufiicient amount to allow the shaft 118 to then move to the right andfree the shaft 85 from the socket portion 120. In the preferredconstruction the pin 126 is of a length sufficient to prevent removal ofand possible misplacement of the spring 130. With the connecting shaft116 being removed so as to decouple the shafts 82 and 85, the guides 36and 38 are separably removable from the truck 10.

Each of the guides 36 and 38 is provided with a plurality of carriers,and inasmuch as the set of carriers provided for each of the guides 36and 38 are identical, being mirror images of each other, a detaileddescription of the set of carriers provided in relation to the guide 36will suffice for both such sets of carriers. The guide 36 is providedwith carriers 134, 136, 138, 140, 142 and 144. Such carriers arebasically of two types, the carriers 134, 138 and 142 being identicalexcept with respect to an additional provision made with respect to thecarrier 134 that will be brought out presently. Similarly the carriers136, and 144 are identical to each other except for the specialadditional provision made with respect to the carrier 144 that will alsobe brought out subsequently. It will be noted that the individualcarriers of the two different types are alternately positioned along thelongitudinal extent of the guide 36. Though equal numbers of the twotypes of carriers are shown in the drawings, such is not essential, itonly being necessary for a reason set forth later that the type ofcarrier 144 be rearmost in the series of carriers.

The type of carriers indicated at 136, 140 and 144 are identical aspreviously explained, and a description of one of such carriers willsuflice for all, and accordingly, attention is directed to FIGURES 3 and4 for an understanding of the structure of the carrier 144. The carrier144 is generally of a cruciform configuration being comprised of anintegral steel vertical member 146 and a horizontal member 148. It willbe noted that the vertical member or portion 146 of the carrier 144extends above and below the horizontal member or portion 148. Thecruciform structure comprised of the members 146 and 148 is disposed onthe side of the guide 36 opposite the side wall 28 of the truck 10, andis spaced from the side wall 40 of the guide as clearly shown in FIGURE3. The cruciform structure has a vertical extent greater than that ofthe guide 36, the horizontal portion 148 thereof being disposed at aheight somewhat less than the bottom of the guide 36, and the verticalportion 144 is provided wi;h a stub axle 150 that projects laterallyfrom the carrier portion 144 horizontally above the top of the guide 36,and a roller or wheel 152 is rotatably mounted on the stub axle 150 asby antifriction means indicated at 154. In the preferred construction,the stub axle 150 takes the form of a headed member that is threadedinto an internally threaded boss formed integrally with the carriageportion 144 as indicated at 156. Such construction enables the roller152 and the antifriction means 154 to be removed for purposes ofinspection, lubrication, repair, replacement or the like. Whereas theroller 152 is illustraded as being formed of metal such as steel, suchconstruction is not essential as will be evident to those skilled in theart, and if desired the roller 152 can be of a synthetic resin orplastic material formed by injection molding or the like, and for suchpurpose nylon as well as other materials can be employed. If the roller152 is made of a synthetic resin such as nylon, the provision ofantifriction bearing means 154 can be eliminated and the roller directlyjournaled on the stub axle 150 in view of the well known low frictioncharacteristics as between steel and synthetic resins such as nylon.When nylon rollers are used, it is more convenient and preferred thatthe stub axles be welded to the carriage with a nylon or brass washerinterposed between the carriage side and the nylon roller. The nylonroller can be releasably retained on the axle by a steel or brass washerand a removable keeper such as cotter pin or split spring ring extendingthrough the axle or seated in an annular groove, as will be evident tothose skilled in the art.

The roller 152 is provided with a peripheral groove 158 having a bottom160, and the upstanding longitudinally extending rib 56 on the top ofthe guide 36 is received within the groove 158 with the upper edge ofthe rib 56 hearing against the bottom 160 of the groove 158.

The illustrated relationship of the roller 152 to the guide 36 is suchthat the sole contact or engagement between the roller 152 and the guide36 is that between the upstanding rib 56 and the peripheral groove 158.It

ference to free rolling of the roller 152 along the top of the guide 36.It will be evident that the accumulation or retention of foreign matteralong the upper edge of the rib 56 is much less likely to occur. It willbe noted that the relationship of the rib 56 to the groove 158 is suchas to prohibit axial movement of the roller 152 and consequently anysuch corresponding movement of the carrier portion 146 so long as therib 56 is received in the groove 158.

The horizontal portion 148 of the carrier 144 is provided withhorizontally spaced lower rollers 162 and 164 that are disposed directlybelow the hollow guide 36, such rollers 162 and 164 being disposed onopposite sides of the vertical portion 146 of the carrier 144, thearrangement being such that the lower rollers 162 and 164 are equallydistantly spaced forwardly and rearwardly, respectively, of the roller152. The rollers 162 and 164 are identical and are mounted on identicalfashion upon the horizontal portion 148 of the carrier 144. As will beseen in connection with the roller 164 shown in FIGURE 3, the roller 164is mounted for rotation by antifriction means 166 on a stub axle 166.The stub axle 166 is illustrated in the drawings as being in the form ofa headed bolt 168 extending through the antifriction means 166, a spacer170 and through a suitable aperture in the horizontal carrier portion148, such headed bolt 168 being detachably fixed to the carrier 144 by anut 172. As in the case of the upper roller 152, the rollers 162 and 164can be readily removed for inspection, repair, lubrication orreplacement, as desired.

The rollers 162 and 164 are as mentioned previously identical to eachother and bear the same relationship to the guide 36, and as shown inFIGURE 3 in connection with the roller 164, the roller 164 hasperipheral profile defined by cylindrical portions 176 and 178 disposedto about in rolling contact the undersurfaces 68 and 70 of the guide 36that are on opposite sides of the slot 66. The peripheral profile of theroller 164 is additionally defined by a radially extending peripheralrib 180 disposed between the cylindrical portions 176 and 178, the axialextent of the rib 180 being such as to slidingly be received in the slot66, the arrangement being such that the rollers 162 and 164 are guidedby the reception of the rib 180 in the slot 66, the rib 180 and the slot66 constituting in effect rib and groove guiding means. It is to beparticularly noted that it is extremely unlikely that foreign mattercould be received or retained in any such position as to impede freerolling movement of the rollers 162 and 164 along the bottom of theguide 36.

As thus far described all the carriers 136, 140 and 144 are identical instructure and in their relationship to the guide 36. It will be notedthat in each instance the carriers have no freedom of movement otherthan linear translation along the extent of the guide 36, and it is tobe particularly noted that the location of the upper roller as beingintermediate the longitudinal positions occupied by the lower rollersprecludes any rotation of the carrier about any horizontal axisperpendicular to the longitudinal extent of the guide 36. Not only islinear translation of the carriers prevented in all directions exceptalong the longitudinal extent of the guide 36, it will also be obviousthat the carriers are precluded from rotational movement about any axis.

Unlike the carriers 136 and 140, the carrier 144 is additionallyprovided with means extending through the slot 66 operatively connectingthe carrier 144 to the lower flight 100 of the endless chain. Such meansare to be seen in FIGURES 3 and 4, and comprises a steel strap or bar184 having a lomer portion 186 secured in vertically adjusted relationto the lower portion of the vertical portion 146 of the carriage 144 bymeans of nuts and bolts 188 extending through aligned slots andapertures provided in the lower vertical portion 146 of the car-' riage144 and the lower portion 186 of the strap or bar 184. Above itsposition of adjustable attachment to the vertical portion 176, the strap184 includes an upwardly inclined portion 190 that terminates in avertical portion 192 that extends upwardly through the slot 62 into thelower portion 74 of the hollow interior of the guide 36. The upper endof the upstanding offset portion 192 of the strap 184 is bifurcated toconstitute a fork 194. As best shown in FIGURE 3, the fork 194 isintermeshed with cross links or rollers 196 of the lower chain flight100.

As thus far described, it will be seen that the slot 66 not only servesa guiding function in combination with the ribs 180 of the lower wheels162 and 164 of all the carriers 136, and 144, but additionally such slot66 enables an operative connection between the carrier 144 and the chainnotwithstanding the fact that the chain is housed within the hollowinterior of the guide 36. It will be clear in view of the foregoing thatthe adjustable connection between the strap 184 and the lower carrierportion 146 enables the carrier 144 to be operatively connected to aselected position along the longitudinal extent of the lower chainflight 100. It is to be understood that the lower chain flight 100 andthe fork 194 engage the chain in the center of all roller frictioneliminating any side draft on the carriage rollers causing them to bindand not run free on the guide 36.

It is to be understood that the rearmost carrier of the carriersassociated with the guide 38 is similarly provided with meansoperatively connecting the same to the chain Within the guide 38.

Proceeding now to a description of the carriers 134, 138 and 142, adetailed description of the carrier 134 will suflice for all. As bestshown in FIGURES 5 and 6 the carrier 134, like the carrier 144, includesan integral cruciform member comprised of a vertical portion 200 and ahorizontal portion 202, the structure 134 diflering from the basicstructure of the carrier 144 in that the horizontal portion 202 isdisposed adjacent the top of the guide 36. The carrier 134 is providedwith a lower roller 204 that is disposed directly below the guide 36,the roller 204 being mounted for rotation by means 206 to the verticalcarrier portion 200, such means 206 being generally similar to the meanspreviously described in the rotatable mounting of the rollers 162 and164. Also like the rollers 162 and 164, the roller 204 has a peripheralprofile identical to that of the roller 164 so as to roll against theunderside surfaces 68 and 70 of the guide 36, and the roller 204includes a radially extending peripheral rib 208 received in the slot 66in the same manner as the rib is received.

The carrier 134 includes a pair of upper rollers 210 and 212 that aredisposed directly above the guide 36 and which are equidistantly spacedforwardly and rearwardly, respectively, of the lower roller 204. Therollers 210 and 212 have peripheral profiles identical to that of thepreviously described roller 152 and bear the same relationship to theguide 36 as that previously described as existing between the roller 152and the guide 36. Furthermore, the upper rollers 210 and 212 of thecarrier 134 are disposed adjacent the opposite extremities of thehorizontal carrier portion 202 and are mounted on rotation thereon inthe same manner as that previously described in connection with themounting of the roller 152.

From the foregoing, it will be seen that the rollers 210 and 212 haveperipheral grooves such as the peripheral groove 158 of the roller 152so as to receive the rib 56 therein so as to support and guide rollingmovement of the rollers 210 and 212. As in the case of the previouslydescribed rollers 152, 162 and 164, the rollers 204, 210 and 212 can ifdeemed necessary or expedient be made of synthetic resins such as nylonor the like, and can be directly journaled on stub axles without theinterpositioning of any antifriction means such as ball or rollerbearings. As in the case of the carrier 144, the freedom of movement ofthe carrier 134 is limited solely to linear 1 l translation along thelongitudinal extent of the guide 36, and the carrier 134 is constrainedagainst any rotation.

The extensible and retractable flexible roof structure 14 comprises alarge generally rectangular flexible sheet of material of waterproofcharacter such as the material of which tarpaulins are conventionallyfabricated, such as heavy cotton duck or nylon material impregnated andcoated with conventional waterproofing materials, such rectangular sheetof flexible material or tarpaulin being indicated at 220. The tarpaulin220 has its greatest dimension extending forwardly and rearwardly and issomewhat greater than the overall longitudinal extent of the truck bed24. The minor or transverse dimension of the tarpaulin 220 is somewhatgreater than the spacing of the side walls 28 and 30 of the truck 10.The forward edge of the tarpaulin is suitably secured by conventionalmeans to the upper edge portion of the front wall 26 at 222. Preferablythe tarpaulin is detachably secured at 222 by conventional snapfasteners for a purpose presently to appear. In the event that the uppermarginal portion of the front wall 26 is detachable from the lower partof the front wall 26, the tarpaulin 220 can be removed from the truck 10therewith as a unit. As is the conventional practice in the case offabric covers or roofs for truck beds, whether such fabric or tarpaulinroof structures are retractable or not, such tarpaulin covers aresupported along the length of the truck bed by a series of spaced bowswhen the tarpaulin extends the length of the truck bed, the spacing ofthe bows and the positions at which the bows are attached to thetarpaulin being such that the tarpaulin is under some degree oflongitudinal tension sufiicient to prevent any substantial degree ofsagging intermediate the bows. Broadly speaking, the tarpaulin 220 isconnected to and supported by bows in the conventional manner, the bowsbeing received within pockets extending transversely across theunderside of the tarpaulin so as to prevent vertical separation of thebow from the tarpaulin as well as to prevent relative longitudinalmovement of the tarpaulin with respect to the bow.

In general all the bows employed in the support of the tarpaulin 220 ofthe present invention are identical to each other and identical in theirconnection or relationship to the tarpaulin 220 and also with respect totheir relation to pairs of carriers of the guides 36 and 80.Accordingly, a detailed description of the rearmost bow 230 which isassociated with the rearmost carrier 144 on the guide 36 and therearmost carrier counterpart of the guide 38 will suffice for the bowsassociated with all the other carriers such as the bows 232, 234 and 236respectively associated with the carriers 136, 138 and 142 and thecounterparts of such carriers on the guide 38. The bow 230 is of agenerally inverted U-shaped configuration including a web or centralportion 238 extending between depending leg portions 240 and 242 at itsopposite ends. The upper ends of the vertical portions 146 of thecarrier 144 and its counterpart on the guide 38 are inclined upwardlytoward the side walls of the truck as indicated at 244 in FIGURE 3, theangle of upward inclination being the same as that of the leg portionsof the bow 230. It will be noted that the upper vertical end portions ofall the carriers of both types are similarly upwardly inclined towardthe center of the truck for connection to their respective bows ashereinafter described in connection with the bow 230 and its connectionto the carrier 144 and its counterpart on the guide 38.

The tarpaulin is along its extent such as to correspond to the positionof the how 230 provided with a pocket extending thereacross aspreviously mentioned, such pocket being shown as including upper andlower portions 246 and 248 between which the bow 230 is slidinglyreceived, the pocket including the portions 246 and 248 are attached toan overlying thickness of the tarpaulin 220 indicated at 250. It will beunderstood that the pocket or loop inclusive of the pocket portions 246and 248 are disposed on the underside of the continuous extent of thetarpaulin 220 and that the same can conveniently be formed of the samecharacter of impregnated fabric and be flexible therewith, thearrangement being such that the bow 230 can be slidably extended throughthe pocket so that the leg portions 240 and 242 can project outwardlyfrom the opposite ends of the pocket. For a purpose presently to bedescribed, the web or central portion 238 of the how 230 is formed oftwo sections 252 and 254 that are connected in a telescoping fashion asclearly illustrated in FIGURE 3, the web portion section 252 beingslidably and extensibly received within a socket structure 256 integralwith the bow section 254. A coiled compression spring 258 is receivedwithin the socket structure 256 so as to yieldingly urge extension ofthe bow section 252 outwardly from the socket structure 256.

The leg portions 240 and 242 of the bow 230 are provided with recessestherein such as indicated at 260 with respect to the leg portion 240,which recesses 260 slidingly receive therein reduced end portion 262 ofthe carrier 144 and its counterpart on the guide 38.

In order to maintain the tarpaulin 220 taut over the extent of the bow236, the opposite ends of an elongated elastic band or strap 270 areattached to a ring 272, the ring in turn being attached to a peripheraledge portion of the tarpaulin 220 by means of a tab 274 stitched orotherwise suitably secured to the tarpaulin 220, it being understoodthat the position of the ring 272 is in transverse alignment with thepocket in which the how 230 is disposed. The elongated elastic member270 is releasably tensioned to be engaged about the underside of aprotruding pin or knob 276 adjacent the lower end of the verticalcarrier portion 146. It will be appreciated that all the carriers areprovided with such pins and coact with similar elastic members formaintaining the tarpaulin 220 tensioned over the respective bows.

The previously described spring biased telescoping web portion 238 ofthe bow 230 (such feature being common to all the bows) is for thepurpose of accommodating the extent of the bow 238 to such variation inthe spacings of the guides 36 and 38 as may occur on the side walls 28and 30 tending to be bulged apart by cargo carried upon the truck bed24, it being noted that such spreading can readily occur in connectionwith somewhat fluid cargoes such as wheat unless the sidewalls 28 and 30are extremely rigid.

As thus far described the operation of the extensible and retractableroof will be readily understood. Assuming that the bows and thetarpaulin 220 are disposed as shown In FIGURE 1 as an initial condition,with the carrier 144 and its counterpart on the guide 38 areappropriately coupled to the lowermost flights 100 of the chains withinthe guides 36 and 38, rotation of the shafts 82 and 85 in a clockwisedirection as seen in FIGURE 6 will result in the chain causing therearmost carriers to be forcibly urged forwardly on their respectiveguides at equal rates. This results in forward movement of the bow 230which carries along therewith the rearmost edge of the tarpaulin 220.Continued forward movement of the bow 230 will continue until thecarrier 144 approaches the position shown in FIGURE 1 of the carrier 142whereupon either direct engagement of the carriers 144 and 142 and/orsome degree of compression of the intervening extent of the tarpaulin220 will cause forward movement of the bow 236 along with the how 230,it being appreciated that the intervening extent of the tarpaulin 220will more or less fold upon itself due to its flexibility in anaccordion-like fashion. Such progressive movement of the rearmost bow230 will successively sweep along therewith and in advance of all thebows associated with the carriers 142, 140, 138, 136 and 134 until thecarrier r134 reaches a position closely adjacent to but spaced from theforward end of the guide 36. Such final position approximates that shownof the structure shown in FIGURE 2. Actually, the carriers will besomewhat closer spaced to each other than shown in FIGURE 2 in suchfinal position of retraction of the roof structure 14, the FIG- URE 2showing of the carriers departing therefrom to make the separateidentities of the individual carriers more apparent. It is especiallyimportant to note that the previously described alternate configurationsof the carriers enable the carriers to occupy a very min-or portion ofthe axial extent of the guides 36 and 38 when the roof structure 14 iscollapsed or retracted inasmuch as the maximum longitudinal extents ofthe carriers are alternately disposed above and below the verticalextents of the guides, whereupon the carriers can be longitudinallynested, so to speak, with respect to each other. This will be evidentwhen it is considered that from the side such carriers have an overallextent compatible with triangular configurations with alternatetriangular configurations having their apices and bases interchanged.The nesting capability of the carriers enables a greater degree ofretraction of the roof structure 14 than would otherwise be the case aswould be evident if all the carriers were of only one of the twodescribed types. a

When it is desired to extend the roof structure 14 to that shown thereofin FIGURE 1 from that approximately shown in FIGURE 2, the shafts 82 and85 are caused to rotate in unison in an anticlockwise direction asviewed in FIGURE 6, whereupon the bow 230 is forced rearwardly until itreaches the position shown thereof in FIGURE 1, it being evident thatthe tensioning of the tarpaulin between successive bows during rearwardmovement of the bow 230 will successively urge the carriers 142, 140,138, 136 and 134 to successively move rearwardly along therewith.Inasmuch as such extension of the roof structure 14 involves or requiresthe transference of force longitudinally along the extent of thetarpaulin 220, it will be understood that the latter may be madesufiiciently strong in its longitudinal dimensions so as to withstandthe tensile stresses to which the same is subjected. Reinforcing canconveniently be by way of securing elongated flexible strips along thelength of the tarpaulin 220, not shown, or by reinforcing the same withflexible links of wire, not shown, appropriately secured at spacedpositions along their lengths to the tarpaulin 220. It may be noted thatthe whole design of the carriers, guides and chain housing is to havethe bows travel the guides with the least amount of drag on thetarpaulin as it is extended from its collapsed position, otherwise ifthe carriers and bow assembly did not roll free, there would be a strainon the tarpaulin where it is fastened to the bows causing it to tear, soextreme care has been taken to have a free running bow and carrierassembly. The intermediate bows are merely to hold up the tarpaulin atevenly spaced intervals, whereas the rear bow assembly holds up thetarpaulin and also stretches it out over the truck bed.

It will be evident that when the relative angular positions of theshafts 82 and 85 are fixed as by connection by the connecting shaft 116,the means by which the rearmost carriers can be detachably secured atselected positions along the lowermost flights of the chains affords theobvious advantage of the carrier 144 and its counterpart on the guide 38being positionable at precisely transversely aligned positions whilealso being coupled to the chains.

Inasmuch as the tarpaulin 220 in its extended condition does not make asubstantially airtight connection with the upper edges of the side walls28 and 30 of the truck 10, there being a minor degree of spacingtherebetween, it will be evident that some degree of air flow can occurthrough such space, and that during rapid forward movement of the truck10 such air flow can become substantial due to the partial vacuumexisting at the rear end of the truck. Inasmuch as the intermediatetransverse extent of the tarpaulin 220 at its rearmost edge is disposedat a height above the upper edge of the conventional tail gate 32, theair flow can be of such a magnitude as to produce a very bad result whenthe cargo is of such semifluid character as wheat. Excessive air flowthrough the space intervening between the tarpaulin 220 and the top edgeof the endgate 32 can in the case of a cargo such as wheat result insubstantial quantities of wheat being carried from the truck andirretrievably lost.

Accordingly, the present invention is provided with means whereby airflow such as could otherwise occur between the upper edge of the endgate32 and the rear edge of the tarpaulin 220 can be greatly reduced.

The means provided for limiting or reducing the freedom of air flowbetween the upper edge of the tailgate 32 and the rear end of thetarpaulin 220 when the latter is in its fully extended positioncomprises a closure member or wall 280 hingedly connected to the upperedge of the tail gate 32 at 282 and 284, it being noted that the hingeaxis is disposed at the rear edge of the juncture 284 of the endgate 32and the closure wall 280 when the endgate 32 and the closure wall 280are in their closing positions shown in FIGURE 8, the arrangement beingsuch that anticlockwise swinging movement of the closure wall 280, asviewed in FIGURE 9, is limited to that shown thereof in full lines inFIGURE 9 by abutment of the adjacent upper and lower edges,respectively, of the endgate 32 and the closure wall 280 in the positionshown in full lines in FIGURE 9. The closure wall 280 can be swung in aclockwise direction as indicated by the arrow 286 in FIGURE 9 to openthe space intervening between the endgate and the extended tarpaulin220. It will be noted that when the closure wall 280 is in its closingposition, both the endgate 32 and the closure wall 280 are vertical andsubstantially coplanar with each other. If desired, the closure wall 280can in its closing position be inclined slightly upwardly and forwardlyso that the upper edge thereof is disposed under the rear edge of thetarpaulin. With such inclination, the rear-ward extent of the tarpaulinneed not be quite so great.

As plainly apparent in FIGURE 9, the guides 36 and 38 extend somewhatrearwardly of the tail gate 32, whereby the bow 230 is disposedsubstantially directly above the endgate 32 and the closure wall 280when the tarpaulin 220 is in its fully extended position. The transverseextent of the closure wall 280 is substantially that of the spacing ofthe side walls 28 and 30, and the closure wall 280 has an upper edgeconfiguration or periphery 288 that substantially complements theunderside contour of the bow 230. Not only is the periphery 288substantially complementary to the bow 230, but the vertical extent ofthe closure wall 280 is such that when the closure wall 280 is closedits upper edge is closely spaced to the bow 230 and the tarpaulin 220carried thereby.

Means is provided for releasably latching the closure wall 280 inclosing position relative to the endgate 32. Such means comprises alatchkeeper fixed to the upper inner edge of the endgate 32 as indicatedat 302. The latchkeeper includes an upstanding offset portion 304 havingan aperture 306 therethrough, and the upper end of the offset portion304 is inclined to define a camming surface 308. As will be apparent oninspection of FIG- URE 10, the upstanding portion 304 extends above thejuncture 284 of the endgate 32 and the closure wall 280. A latch bolt310 slidably extends through an opening 312 through the closure wall280, the opening 312 being in alignment with the aperture 306 when theclosure wall 280 is in its closing position as shown in FIGURES 8 and10. The relationship is such that the latch. bolt 310 can extendhorizontally through the aperture 306 so as to prevent swinging movementof the closure wall 280 about the pivotal axis 314 defined by the hinges282 and 284. Compression spring means 316 embraces the latch bolt 310intermediate the forward side of the closure wall 280 and a radiallyextending pin 318 on the latch bolt 310. As will be appreciated oninspection of the drawings, the spring 316 yieldingly urges the latchbolt 310 into a position such as to be received through the aperture306. The end of the latch bolt 310 on the rear side of the closure wall280 is provided with a pull ring 320 by means of which the latch bolt310 can be pulled from engagement with the latchkeeper 300 against thebias of the spring means 316, whereby the closure wall 280 can bereleased and swung into an opening position as indicated by the arrow286 in FIGURE 9. The pull ring 320 limits the extent of movement of thelatch bolt 310 in the direction urged by the spring means 316, and suchextent of the movement of the latch bolt 310 is such that the end 322 ofthe latch bolt 310 will engage the carnming surface 308 so as to permitthe closure wall 280 to be moved into its closing position with thelatch bolt 310 then passing into locking position in the aperture 306.

Attention is now directed to means whereby the chain sprocket shafts 82and 85 are reversely and forwardly driven into unison by a truckoperator situated in the operators cab 12. Such means are electrical andinclude a reversible direct current motor 330 mounted in any suitablemanner upon the front side of the truck bed front Wall 26 at a positionbelow the connecting shaft 116. Preferably, the reversible directcurrent motor 330 is mounted upon a fixed portion of the front wall 26(that is, below any detachable upper portion of the front wall 26), anda reduction gear box 332 is also mounted upon such fixed portion of thefront wall 26, the output shaft 334 of the motor 330 being connected tothe input of the gear box 332, and the output shaft 336 of the gear box32 is provided with a fixed chain sprocket 38. An endless chainindicated schematically at 340 in FIGURE 6 is entrained over the chainsprocket 338 and a chain sprocket 342 fixed to the shaft 82 at aposition intermediate the connecting shaft 116 and the guide 36. Ifdesired, though not shown, a housing can be detachably secured to thefront wall 26 to protect the motor 330, the gear box 332, the sprockets338 and 342 and the chain 340 from the elements, and especially tosafeguard persons from accidentally coming into contact therewith.

As thus far described, it will be evident that the motor 330 can beselectively driven in rotation in either direction with the speed ofrotation being substantially reduced by the gear box 332 (which can be adouble worm gear type) and such reduced rate of rotation imparted withstill further reduction (by virtue of the relatively larger size of thesprocket 342) to the shafts 82 and 85. As previously explained, thedetachable coupling of the shafts 82 and 85 is such as to assure theirrotating in unison.

Attention is now directed to the electrical circuitry associated withenergizing the electric motor 330 selectively to rotate in a forward ora reverse direction, or to stop entirely. It may be interjected at thispoint that when the motor 330 is deenergized, the reduction gearing 332coupled with the usual amount of friction in such apparatus and in themotor 330 serves to lock the shafts 82 and 85 against rotation, at leastagainst such forces as may be imposed thereon by wind action, and soforth, on the tarpaulin 220. The electrical circuitry is shown in FIGURE7, wherein the reference numeral 350 designates an electrical battery,such battery 350 preferably being the storage battery conventionallyincluded as an integral part of the ignition, lights, etc., system ofthe truck 10 and disposed in the engine compartment 16 thereof. Oneterminal of the battery 350 is grounded to the frame of the truck 10 asindicated at 352. A pair of electrical relays 354 and 356 are provided,such relays being identical and respectively including solenoids 358 and360 and normally open solenoid actuated switches 362 and 364. The relays354 and 356 are enclosed in a housing 366, and such relay housing 366is, like the motor 330 and the gear box 332, mounted on the front wall26 of the truck 10. One terminal each of the solenoids 358 and 360 isgrounded, as by leads 368 and 370 so as to be in electrical engagementwith the grounded terminal 352 of the battery 350.

The solenoids 358 and 360 are normally not energized and theirrespective switches 362 and 364 are therefore normally open; however,means is provided for selectively energizing the solenoids 358 and 360from the ungrounded terminal of the battery 350, such means comprising aconductor 374 connected between the ungrounded terminal of the battery350 and the movable contact 376 of a normally open single pole, doublethrow switch 378, the switch 378 being conventional and of the typespring biased to its open position. The conductor 374 is fused at 380.Inasmuch as the solenoids 358 and 360 draw very little current theconductor 374 can be relatively fine wire, and the fuse 380 a fuse ofcorrespondingly low value. One of the fixed contacts 380 is connected bya conductor 382 to a normally closed microswitch 384, such microswitch384 being in turn connected by a conductor 386 to the ungroundedterminal of the solenoid 358. Similarly, the other fixed contact 388 ofthe switch 378 is connected by a conductor 390 to a normally closedmicroswitch 392, such microswitch 392 being in turn connected by aconductor 394 to the ungrounded terminal of the solenoid 360. As in thecase of the conductor 374, the conductor 382, 386, 390 and 394 can be oflight wire of relatively low current carrying capacity.

As thus far described, the movable contact 376 of the switch 378 can bepressed from its normal position into contact with the contact 380,whereupon (provided the microswitch 384 is closed) the solenoid 358 isenergized and the switch 362 actuated from its normally open position toits closed position. In a similar manner the contact 376 can be pressedinto engagement with the Contact 388, whereupon the solenoid 360 can beenergized to close the normally open switch 364. It will be understoodthat the switch 378 is disposed within the operators cab 12 in aposition conveniently accessible to the operator of the truck 10'.

The reversible direct current motor 330 which can conveniently be of thetype conventionally employed in connection with electrically actuatedmeans for raising and lowering the tops of convertible type automobilesincludes three terminals, one of which is grounded as indicated at 396,and a pair of terminals 398 and 400. As will be well understood by thosefamiliar with reversible direct current motors of the type described,the maintenance of a direct current electric potential between theterminal 400 and the ground 396 will cause the motor 330 to run in onedirection, while application of such a potential between the terminal398 and the grounded terminal will cause rotation of the motor 330 inthe opposite direction. The relay switches 362 and 364 selectivelycontrol the application of a direct current electric potential to themotor terminals 398 and 400-. The motor terminals 398 and 400 areconnected respectively by conductors 402 and 404 to the stationarycontacts of the switches 364 and 362, respectively, and the movablecontacts of the switches are connected together by a common conductor406 to the ungrounded terminal of the battery 350. The conductor 406 isprovided with a fuse 408. Inasmuch as the electric motor 330 will draw asubstantial amount of current, the relay switches 362 and 364 arepreferably of heavy duty type, and the conductors 402, 404 and 406 arerelatively heavy conductors appropriate to the current carried by thesame. Similarly, the fuse 408 will have a higher amperage rating thanthe fuse 380. While the electric motor 330 can be of the same powerrating as those employed in connection with the raising and loweringmechanism of the tops of convertible type automobiles, it is preferredthat the motor 330 have a somewhat higher power rating so as to be morepositive in action, or so as to enable relatively greater speeds ofextension and retraction of the roof structure 14 of the truck 10.

As thus far described, the electric motor 330 is normally deenergizedand the roof structure 14 will remain in whatever position it happens tobe disposed. At the option of the operator of the truck 10, he maymanually and selectively actuate the movable contact 376 of the switch378 into electrical engagement with either of the stationary contacts380 and 388. Thus, assuming that engagement of the contacts 376 and 380with each other causes rotation of the motor 330 in such a direction asto drive the sprocket 80in a clockwise direction as viewed in FIGURE 6,the operator of the truck can by such operation of the switch 378 causeretraction of the roof structure 14 from the position shown thereof inFIG- URE 1. Should the operator decide that he desires the roofstructure 14 to occupy a position intermediate its fully extended andretracted positions, the operator simply disengages the contacts 376 and380 when the roof structure 14 reaches its desired position. If theoperator desires that the roof structure 14 be driven to its fullyretracted position, he simply maintains the movable contact pressed intoengagement with the fixed contact 380 until the roof structure 14 isfully retraced. In order to avoid burnout of the motor 330 or blowing ofthe fuse 408 when the roof structure 14 reaches its fully retractedposition, means is provided for deenergizing the motor 330 againstfurther retracting effort, and such means comprises the previouslymentioned microswitch 384 and a switch actuating finger 410 fixed to ormounted on the carriage 142 to project toward the side wall 28. Themicroswitch 384 is mounted on the side wall 28 of tthe truck in thetravel path of the finger 410 and is disposed longitudinally along theside wall 28 to be at a position such as to be engaged by and caused toopen by the finger 410 when the forward movement of the carrier 134 hasbeen such as to have reached the position occupied thereby when the roofstructure 14 is fully retracted. It will also be noted that it is notessential that a finger 410 be on the carrier 142, but the finger 410'can be disposed on the carrier 144, in which event the longitudinalposition of mounting of the microswitches 384 and 392 on the side wall28 will be appropriate to the positions occupied by the carrier 144 whenthe latter is in its position corresponding to full retraction and fullextension of the roof structure 14.

In view of the interaction between the actuating finger 410 and themicroswitch 384, the switch 384 will be open when the roof structure 14is forwardly driven to its fully retracted position, and thusdeenergizes the motor 330 even though the operator maintains the contact376 in contact with the contact 380. i

Inasmuch as the carrier 142 occupies a particular position when the roofstructure 14 is fully extended, the microswitch 392 is mounted on theside wall 28 at a position rearwardly of the microswitch 384 and suchthat the same will be actuated into its open position by the finger 410when the carriage 142 reaches the position occupied thereby when theroof structure is fully extended. It will be understood that when theroof structure 14 is in its fully retracted position such that themicroswitch 384 is open, the fact that the microswitch 384 is open doesnot interfere with energization of the motor 330 in the directionresulting from engagement of the movable contact 376 with the stationarycontact 388 of the switch 378, and consequently, such contacts can beclosed and the roof structure 14 actuated to move towards its extendedposition. As soon as such extension movement is sufficient to disengagethe finger 410 from the microswitch 384 has occurred, the operator canstop further extension of the roof structure and close the contacts 376and 380 if he so desires so as to cause retraction movement of the roofstructure 14. However, if the operator simply continues extension of theroof structure 14 by maintaining the contacts 376 and 388 closed,

7 the roof structure 14 will move to its fully extended position on theoccurrence of which the finger 410 actuates opening of the microswitch392 and consequent deenergization of the motor 330. Thus, the electricalcontrol means is disabled or rendered inoperative insofar as energizingthe motor to rotate in a direction corresponding to movement of the roofstructure in such direction when the latter has reached the limit of itsfreedom of movement.

As mentioned previously, the microswitch actuating finger 410 need notbe on the carrier 134 but can be disposed on the carrier 144. While theillustrated and described embodiment of the invention employs a singlemicroswitch actuator finger 410 for actuating both the microswitches 384and 392, it will be evident that separate actuator fingers on separatecarriers could be provided if desired, one finger and its associatedmicroswitch being disposed at a greater height than the other finger andits associated microswitch.

In the normal use of the apparatus the forward end of the truck bedremains covered. This does not preclude filling the forward end of thetruck to a substantial ex tent with wheat or the like considering theflowing character of the wheat. However, to obtain complete filling ofthe front end of the truck (especially those having a long bed so as tonecessitate a greater number of bows), the operator can follow a simpleprocedure to accomplish this objective. The operator retracts the roofstructure, and by means ofshort lengths of rope or chain, not shown,secures at each side of the truck the forwardmost and rearmostcarriages. He then detaches the front end of the tarpaulin from thefront wall of the truck bed and folds the freed portion of the tarpaulinforward of the front bow back over the top of the rest of the tarpaulin.Then with the front and rear carriages (and bows) secured againstrelative separation movement, the operator drives the apparatus to movethe rear bow rearwardly whereupon the entire roof structure in acollapsed condition moves rearwardly as a unit and uncovers the frontend of the truck bed. After loading the front end of the truck theforegoing steps are performed in reverse to restore the apparatus to itsoriginal condition.

If desired, an additional partition can be disposed within each of thehollow guides above the partition 70. Such partition can be at such aheight that the upper chain flight will be supported thereon with verylittle sag. This provision will tend to reduce any tendency for thechain to slap on variations in the tension thereof in the use of thesame.

Whereas electrical means are disclosed to drive the chains, it will beevident to those skilled in the art that hydraulic and pneumaticequivalents may be substituted for such electrical means, it being notedthat many present day trucks are equipped with hydraulic and pneumaticpower sources.

I claim:

1. In apparatus for the guided support and movement of a retractable andextensible flexible roof structure of the type including a pair ofparallel elongated support guides adapted to be mounted horizontally onthe opposite sides of the roof-coverable area, and a plurality of roofbow support means guidingly supported on each of the guides, theimprovement comprising each of said guides being hollow and having anendless drive chain extending therein within the hollow thereof,sprockets carried by the guide adjacent the opposite ends thereof withsaid endless chain being entrained over said sprockets, each of said bowsupport means including a supported and guided member disposedexternally of the hollow guide, vertically spaced laterally projectingstub axles on said member, an upper roller rotatably mounted on theuppermost of said stub axles, said upper roller being disposed on top ofthe guide and in peripheral rolling engagement thereon, with the top ofthe guide and the circumferential periphery of the upper roller havingmeshing rib and groove means for preventing axial movement of the upperroller relative to the guide, a lower roller rotatably mounted on thelowermost of vthe stub axles, said lower roller being disposed on thebottom of the guide and in close peripheral rolling proximity 19thereto, with the bottom of the guide and the circumferential peripheryof the lower roller having meshing rib and groove means for preventingaxial movement of the lower roller relative to the guide, said guidehaving a longitudinally extending slot in the bottom thereof openinginto said hollow, and at least one of said support means being providedwith an upright member having an operative connection with the chainthrough said slot.

2. The combination of claim 1, wherein said rib and groove meanspreventing axial movement of the lower roller is defined by the slot andby the lower roller having a peripheral rib received in said slot.

3. The combination of claim 1, wherein said rib and groove means forpreventing axial movement of the upper roller comprises the guide havingan upstanding longitudinally extending rib on the top thereof directlyoverlying the endless chain, and by said upper roller having aperipheral groove receiving said rib.

4. The combination of claim 2, wherein said rib and groove means forpreventing axial movement of the upper roller comprises the guide havingan upstanding longitudinally extending rib on the top thereof directlyoverlying said slot, and by said upper roller having a peripheral groovereceiving said rib.

5. The combination of claim 1, including a longitudinally extendingpartition in the hollow of said guide dividing the interior thereof intoupper and lower portions, said endless chain having upper and lowerflights between said sprockets disposed respectively above and below thepartition.

6. The combination of claim 5, said slot together with a peripheral ribon the lower roller constituting the rib and groove means for preventingaxial movement of the lower roller relative to the guide, and saidoperative connection of the upright member to said chain comprising themember including an offset upstanding portion projecting upwardlythrough said slot and into operative engagement with the lower flight ofthe chain.

7. The combination of claim 6, wherein the offset upstanding portion ofthe member is vertically movable relative to the latter, means forreleasably securing such offset portion against movement relative to themember, and said offset member having a bifurcated upper end projectingupwardly into meshing engagement with the chain, whereby the member canbe operatively connected to the chain at a selected position along thelength of the endless chain.

8. The combination of claim 1, wherein the member of solely alternatesupport means is provided with a second upper stub axle and rollercorresponding in its relationship to the guide to the first mentionedupper stub shaft and upper roller, said upper rollers being spacedlongitudinally relative to the longitudinal extent of the guide and insuch longitudinal sense being disposed on opposite sides of thelongitudinal position of the lower roller, whereby tilting of the memberabout a horizontal axis transverse to the longitudinal extent of theguide is prevented.

9. The combination of claim 1, wherein the member of solely alternatesupport means is provided with a second lower stub axle and rollercorresponding in its relationship to the guide to the first mentionedlower stub shaft and lower roller, said lower rollers being spacedlongitudinally relative to the longitudinal extent of the guide and insuch longitudinal sense being disposed on opposite sides of thelongitudinal position of the upper roller, whereby tilting of the memberabout a horizontal axis transverse to the longitudinal extent of theguide is prevented.

10. The combination of claim 1, wherein a plurality of bow support meansare provided that are disposed in a sequence longitudinally along eachof said guides with adjacent bow support means being relatively movablewith respect to each other in the. direction of the longitud n w nt 9 hg r t and seems a j n 29W support means respectively having greater andlesser longitudinal extents at the upper stub axle, said first andsecond bow support means respectively having lesser and greaterlongitudinal extents at the lower stub axle, such first and second bowsupport means being so constructed and arranged that they can be movedinto such close proximity that the first of such means can partiallyoverlie the second of such means, said first bow support having a secondupper stub axle and roller with the lower roller of such first bowsupport means being disposed longitudinally intermediate the upperrollers thereof, said second bow support means having a second lowerstub axle and roller with the upper roller of such second bow supportmeans being longitudinally intermediate the lower rollers thereof,whereby the sequence of the plurality bow support means can be nested.

11. Apparatus for supporting, guiding and moving a carrier comprising anelongated and horizontally extending hollow guide, said guide having alongitudinally extending slot opening into the interior thereof, acarrier disposed at a side of the guide and provided with verticallyspaced upper and lower rollers respectively disposed above and below theguide to engage the top and bottom of the guide, a pair of chainsprockets mounted adjacent opposite ends of the guide, an endless chaindisposed within the guide and entrained over the sprockets, and meansextending through the slot and operatively connecting the carrier andthe chain.

12. Apparatus for supporting, guiding and moving a carrier comprising anelongated and horizontally extending hollow guide, said guide having alongitudinally extending slot opening into the interior thereof, acarrier disposed at a side of the guide and provided with verticallyspaced upper and lower rollers respectively disposed above and below theguide to engage the top and bottom of the guide, a pair of chainsprockets mounted adjacent opposite ends of the guide, an endless chaindisposed within the guide and entrained over the sprockets to definechain flights between the sprockets, said guide having an internalpartition disposed between and separating the chain flights, and meansextending through the slot and operatively connecting the carrier andone of the chain flights, said slot being in the bottom of the guide,and said lower roller having a peripheral rib received in said slot.

13. The combination of claim 12, including a partition in the guideseparating the hollow interior thereof into upper and lower portions,and said endless chain having upper and lower flights disposedrespectively in the upper and lower portions of the hollow interior.

14. In the combination of a self-propelled cargo vehicle of the typeincluding a truck bed having an upstanding front end wall, spacedupstanding side walls, and a rectangular endgate pivotally mounted alongan edge to the rear edge of the truck bed with a retractable andextensible roof of flexible material having a front edge secured to thefront end wall and supported by a series of relatively movable bowssupported and guided for forward and rearward movement upon guidescarried by the side walls; the improvement wherein each of the bows isgenerally of an inverted U-shaped configuration including depending legportions connected by a web portion, and wherein the bows are supportedand guided by a pair of longitudinally hollow guides carried by andextending along the side walls, each leg portion of each bowbeingprovided with a carrier movably mounted on one of said hollow guides,said hollow guide having a longitudinally extending slot in the bottomthereof openinginto the hollow interior of the guide, said hollow guidehaving a longitudinally extending rib along the top thereof, saidcarrier having an upper roller on the top of the guide, such upperroller having a peripheral groove receiving the rib therein, saidcarrier having a lower roller on the bottom of the guide, such lowerroller having a p ph al rib rewind i th s o d ivin and driver chainsprockets mounted on the guide adjacent the opposite ends of the guide,and an endless chain within the hollow guide and entrained over thesprockets, means operatively connecting the carriers of the leg portionsof the rearmost bow to the chains within the guides, the last recitedmeans extending through the slots of the guides, and means forreversibly driving the driving sprockets in unison.

15. The combination of claim 14, wherein the means for reversiblydriving the driving sprockets in unison includes said driving sprocketsbeing mounted on a common drive shaft, and said drive shaft beingcomprised of two separate sections, and means for detachably securingthe shaft sections together.

16. The combination of claim 14, wherein said means for reversiblydriving the sprockets includes electrical control means comprisingforward and reverse circuits, and means responsive to the warmest bowbeing disposed at relative forward and reverse positions to disablerespectively the forward and reverse circuits.

17. The combination of claim 14, wherein each bow is provided with meansenabling variation in the spacing of References Cited UNITED STATESPATENTS 1,602,017 10/1926 Hamilton 296-105 2,084,733 6/1937 Kahlifi49-199 3,326,598 6/1967 Kunsch 296105 LEO FRIAGLIA, Primary Examiner I.E. SIEGEL, Assistant Examiner U.S. Cl. X.R. 160188

